Rotary control shafts are utilized in control mechanisms for hydrostatic transmissions to selectively actuate the same. Various single-pedal actuated linkage systems have been proposed for use in such control mechanisms to effect selective rocking of the control shaft. Conventional linkage systems of this type are oftentimes unduly complex and place high stress concentrations on component parts thereof. In addition, relatively high initial starting torques are required to displace the control mechanisms from their neutral conditions of operation.
A single pedal is normally used to simultaneously actuate a throttle control lever for varying engine speed. The pedal force required to further increase engine speed, once the transmission has been placed in a full-speed forward or reverse condition of operation, is normally relatively high in conventional systems.